202 



THE AGRICULTURAL NEWS. 



June 18, 1904. 



INSECT NOTES. 



St. Vincent. 



The fallowing extracts are taken from a report, 

 dated May 23, by Mr. H. A. Ballon, B.yc, Entomolo- 

 gist on the staff of the Imperial Department of 

 Agriculture, on a vi.sit recently paid to St. Vincent: — 



At the Agricultural School no serious attack of insect 

 pests was noticed. 



The cotton which was attacked by the leaf-blister mite 

 had all been pulle<l out and burned, and no evidences of the 

 [ireseuce of this pest were to be seen. 



A papaw tree in the garden plots was seen to be 

 attacked by the white scale (Dia-y^is amt/fi<la)i). A few 

 si)eciniens of the golden wee^■il {Dicq>re2^e!t apeniileri) were 

 collected. This sjiecies is closely related to the lady-bird 

 root-borer of the sugar-cane (Diaprepes ahhreviatus) and was 

 very abundant last year in June when I visited St. Vincent. 

 The apjiearance of a few specimens at this time would 

 indicate that May and .June are the season for the emergence 

 of the adult. The food of the larva is not known, but it is 

 probably a borer or root feeder. The adult has a variety of 

 food plants, being found this year princijially on citrus 

 plants, and last year on pigeon pea and a few cruciferous 

 l>lants. 



At the cotton factory large numbers of cotton stainers 

 were seen feeding on cotton seed which was scattered 

 about the ground. This would be a good opportunity for 

 trai>ping and killing these bugs in large numbers. When 

 they are collected on the cotton .seed, they might be killed 

 either with hot water or kerosene. 



At the Botanic Station very few insects were to be seen 

 in sutticientlj large numbers to do any damage. The most 

 noticeal)le case was that of several Lilierian coffee trees 

 attacked by the Shield scale (Lecaniuni. he.y^erkfniii). 

 Jlr. Sands was recommended to try on these trees Lefroy's 

 mixture (crude IJarbados oil, and whale oil soap). In 

 the nursery a few insects were noticed. These were all 

 in very small numbers, however, and evidently held well in 

 check by spraying. 



JIany of the plants in the gardens are sprayed every 

 week and, with the excei)tion of the coffee trees already 

 mentioned, good results .seem to have been accomplished. 



Onion Thrips. 



Amrricnn Gardcnin;/ of May 7, 1904, contains 

 an interesting account of the onion thrips {Thrips 

 fiihac'i), of which the following is a brief summary : — 



This pest received its specific name from the fact that it 

 was first observed in Europe attacking tobacco. In 1872, 

 Dr. Packard called attention to it as a serious pest of onions 

 in eastern ^Massachusetts where the damage in one county 

 alone amounted to .$10,000. Comparison by experts proved 

 that the onion pest of the New World and the tobacco jiest of 

 Euroiie were identical. 



REMEDIES. 



Ivori/ sidjiliur sitds: This mixture is made by di.s.solving 



1 &. of ivory soaj) in i gallon of boiling rain water and 

 .stirring in 1 It), of flowers of sulphur, while the .soap solution 

 is still hot. This is the stock solution. For use, 1 pint is 

 dissolved in a little hot water and made U[< slowly to 

 4 gallons. This wash can be sprayed on to the leaves and in 

 addition to its insecticidal properties it would probably have 

 .some effect in preventing attacks of fungi, which might enter 

 through the jpunctures made by the insects. A few days 

 after the aiijilication of the soap-sulphur wash, clear water 

 should be sjirayed on to the jilants. A heavy shower in the 

 meantime would probablj- make this uiniecessary. 



Tobacco: Refuse tobacco, tobacco stems and tobacco 

 dust may lie used in solution or dry. The solution is 

 prejiared by soaking tobacco stems or refuse in cold water for 

 a day or two, aral using the liquid as a si^ray. 



Wha/e oil soaj) : This is also mentioned as efficient at 

 the rate of 1 lb. of soap to 8 gallons of water. 



These washes have all been tried in greenhouses 

 with success on several species of thrii)s, and it is believed 

 that they would be equally efficient in the onion field. 

 Tobacco, applied dry as a dust and as a mulch about the 

 plants, has also given good results. 



CULTURAL METHODS. 



Professor Webster foiuid the onion thrips in Ohio 

 breeding in the grasses and wikl plants in the vicinity of 

 onion fields and in the refuse left on the onion fields. As 

 an essential cultural method, therefore, it is recommended 

 that the eilges of the fields be keiit free front all weeds and 

 plants on which this pest might breed. Professor Webster 

 is quoted as saying : ' It has been demonstrated that the 

 insect can be destroyed by sjiraying the plants along the 

 edge of the onion helds when they first begin to show the 

 effects of attack, using 1 lb. of whale oil soap to 8 gallons of 

 water.' 



These remedies seem to have been more successful in 

 the United States of America than in the West Indies, 

 where they have all been tried except the soap-suljjhur wash. 

 In addition to these the soda-sulphur wash has been tried, and 

 while it has perhaps given better results than the others, 

 yet it has not Vieen entirely successful. This is made by 

 Ixiilicg 2 H). caustic .soda and 1 It), sulphur in a small amount 

 of water till dissolved. This forms stock solution sufficient 

 for 10 gallons of spray. 



References to thrips of onions and cacao will be 

 found in the Weft Indian Bvlldin (Vol. II, pp. 17G 

 and 2^<8) and in the Acjricidtural News (Vol. II. p. 88, 

 and Vol. Ill, p. 10. 



THE AGE OF EGGS. 



An ingenious method for determining the age of eggs 

 has been awarded a medal by the National Society of Poultry 

 Breeders of Saxony It is well known that the air cavity at 

 the blunt end of the egg enlarges as the age of the egg 

 increases, consequently, if an egg be placed in a 1 :2 solution 

 of common salt, it will have an increasing tendency to float 

 with the long axis vertical. A .scale of angles is placed at the 

 back of the salt bath, and, from the inclination of the egg to 

 the horizontal, the age can be gauged almost to a day, 

 A new-laid egg lies horizontally on the bottom of the vessel, 

 when three to five days old the blunt end is raised, .so that 

 its long axis makes an angle of about 20' with the horizontal, 

 at eight days this increases to 4.5', in fourteen days to 60°, 

 and in three weeks to about 7.")°, while in a month it stands 

 upright on the pointed end. {Scientific American.) 



